/**
 * Copyright 2009 Emory University
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated  * documentation files (the 
 * "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions: The above copyright notice and this permission
 * notice shall be included in all copies or substantial portions of the
 * Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
 * EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
package com.markgrand.structuredSql;

/**
 * Trait for classes that append SQL to StringBuilder objects.
 * 
 * @author Mark Grand
 */
trait SQLAppender {
    /**
     * Append SQL source to the given StringBuilder.
     * 
     * @param builder
     */
    def append(builder:StringBuilder) 

    /**
     * Return a String built by the append method.
     */
    override def toString = {
        val builder = new StringBuilder();
        append(builder);
        builder.toString();
    }
       
    protected def appendSeq(appenders: Seq[SQLAppender], builder:StringBuilder) {
      appendSeq(appenders, builder, ",")
    }
    
    protected def appendSeq(appenders: Seq[SQLAppender], builder:StringBuilder, separator:String) {
      val appenderIterator = appenders.iterator
      if (appenderIterator.hasNext) {
        appenderIterator.next.append(builder)
        while (appenderIterator.hasNext) {
          builder.append(separator)
          appenderIterator.next.append(builder)
        }
      }
    }
}
